Draft-regulator for fire-tube boilers.



C. H. MUGALL.

DRAFT REGULATOR EOE FIRE TUBE BOILERS: APPLIOATION FILED FEB.11, 1911.

Patented Apr.23,1912.

aff/Z006@ nutren sangles rara*l enhances n. Masern, or ATLANTA, suonerie.l

nnarrLnns-unaron. ron rien-'ruina nornnns.

Patented npr, as, 191.2.

Application tiled February 11, 1911. Serial No. 607,943.

" Be it known that I, CHAnNooK I-I. Mof

CALL, a citizen of the United States, residing at Atlanta` in the county of Fulton and State of Georgia, have invented certain new and useful Improvements' in Draft-Regulators for Fire-Tube Boilers, of which the following is a. specilication. v

My invention relates broadly to draft regulators or dampe'rs, and more particularly to regulators for re tube boilers.

The invention has special utility when applied to locomotives, as by its use the dangerous throwing of sparks can be entirely eliminated, and also a more uniform tem'- perature maintained, and a saving in fuel effected. 4

In order that my ,invention may be clearly underst-ood,.reference is had to the accompanying drawing, forming a part of this specification, and in which Figure 1 is a side elevation, partly in sec tion, showing my invention as applied to a locomotive boiler. Fig. 2 is a front elevation of the same, the boiler shell being in section, and parts being broken way.

Referring to the drawings in detaihwhich show the invention as applied to a fire tube boiler of the locomotive type, 1 designates the boiler shell, and 2 the usual stack, communicating with the smoke box. Attached tot-he front tube sheet 5 is a T 3, from which extend steam pipes t to the cylinders, (not shown), as usual.

6- designates the lire tubes, which are beaded into the tube sheet 5, andwhich ex- -tend back through the boiler to the re boX, 4('notshown), as will be readily understood,

In the smoke box, between the ends of the tubes and the stack, I arrange a suitable pivoted support, shown here as a baille plate.

This plate, for convenience, may be formed in 'two' or more sections, 7, 8, as illustrated, and is secured at its upper edge to a shaft 9, supported in suit-able"bearingsadjacentl the tube sheet, and extending transversely through the boiler shell. Securedl to the inner face of this battle plate, and projecting at substantially right angles thereto, is a plurality of `individual dempers or studs 10, arranged so as to enter. the respect-ive fire tubes, and control the draft therethrough. The plugs are somewhat smaller than the internal diameter of the lire tubes, and arel preferably formed with beveled or otherwise tapered ends, 11, as shown.. By virtue of thesetapered ends, the plugs serve to obstructthe tubes more and more, as they are ,forced farther in. In order that the dampers may be controlled by the engineer or fireman, I secure a crank lever l2 'to the end' such as indicated at 14, such lever having associated therewith an arc shaped rack 15,-

With which a pawl carried by the lever, and

controlled by a hand grip 16, is adapted to engage, to lock the lever in any desired position.

The operation of the device will be apparent. When the engineer desires full draft, he will set the lever 14 so as to hold the baille plate'away from the tube sheet as far as possible. 'When however, a less dra-ft is sufficient, as where running slowly, or

down hill, or where it becomes necessary-to` suppress the sparks, the shaft 9 is rocked by leve-r 15 so as to bring the bae plate close to the tube sheet, and to cause the tapered plugs to enter the ends of the tubes to a greater or less extent. When in this position the products of combustion are compelled to pass through the restricted spaces between the plugs and the Walls ofthe tubes, and then under andl around the baille plate, andit is evident thatno dangerous sparks can escape through this tortuous passage.

It will thus be seen that I have provided a very simple and eiicient-draft regulator for lire tube boilers, and it isthought the many advantages of'my improved arrangement will be readily appreciated by those familiar with such matters.

1. The combination with a'. re tube boiler having a tube sheen-of a, support pivotally mounted adjacent said tube sheet, and a plus rality of plugs carried by said-support, and arranged to enter the ends of the tubes as the support is swungen its pivot, the length of said plugs increasing in proportion to their distance from the pivot.

2. The combination with a lire tube 'boiler having a tube sheet, of a baiileplate'arranged adjacent said ,sheet and hinged at one edge to t-he boiler, a plurality of plugs secured to said batlie 'plate and adapted to enter the tubes, the length of said plugs varying in propprtionto ltheir 'dist-ance from Ysuch hinged edge, and means for swinging said plate units hinges so as toloree saidA the length o1 said plugs increasing in proplugsinto seid -tubes to a greater or less l portion to their distance from said shaft, extent. and means for rocking said shaft sov as to 3.'Tl1e combinatio with a tire tube boiler swing said baille plate toward and away 5 of the locomotive type, of :L horizontal shaft tfrom the tube sheet.

'ournalededjacent the front tube sheet, a l in testimony whereof l aix my -signature aille plate secured at its upper edge to said in presence of two' Witnesses. .shaft and arranged VWit-loin the smoke box I. CHARNOCK H. MCCALL. between vthe said tube sheet and the smoke I Witnesses:

- 10 stack, plugs carried by said baille plate and W'. K; ILLER Jr., gdapte'd to enter the endsof the fire tubes, FRANK L. MALONE. 

